rossb Posted March 23, 2014 Share Posted March 23, 2014 I have a pair of Exposure 16 mono amplifiers. These are massive monoblock amplifiers, which although they only put out 120 watts each, have two 500VA transformers a piece and weigh about 30kg each. The problem is that they have no soft start. So whenever I switch them on they draw so much current that they trip a fuse in the house (and sometimes the amp as well). When I want to turn them on, I need to have everything connected and switched on in my room, then I flip the fuse switch at the switch box to power the entire system on at once (and everything else sitting on that circuit). This is obviously far from ideal. They are stunning amps and I do not want to replace them, but I would like to know if anyone has any ideas for dealing with this. I understand that there are DIY soft start kits - eg this one:http://www.ebay.com/itm/Diy-Amp-Start-Soft-Starting-Switch-Circuit-Full-Kit-For-Power-Amplifier-/181216616693?pt=US_Home_Audio_Amplifiers_Preamps&hash=item2a315a20f5. I would need to get a technician to install it, but are these things of reasonably quality and would it compromise the audio quality of these amps? I would rather not perform surgery on them unless absolutely necessary. They are extremely rare and not easily replaceable, as well as great sounding. Is it possible to get a fuse which is less likely to trip when a big load goes through it? If so, would this be the better solution? Link to comment Share on other sites More sharing options...
Telecine Posted March 23, 2014 Share Posted March 23, 2014 Do you run RCD's (Residual Current Devices) in the 'fuse box'? If so, I can provide the details of an RCD product that we use that should resolve the issue. I am not sure how easy it would be to fit them in a domestic situation but they solved a problem whereby power inrush was tripping our RCD's in a Data Centre. The devices that were tripping the circuits on power on are massive so you amps won't be an issue. A sparky should be able to advise you on their suitability for a domestic situation. The company might even have a scaled down version for domestic situations. It wasn't an inexpensive exercise but I had a lot to replace. Link to comment Share on other sites More sharing options...
ngquan Posted March 23, 2014 Share Posted March 23, 2014 Are you sure they have no soft start?. Otherwise i would recommend aussieamp soft start module. They would need to be wire with the primary side of the transformer. Quan Link to comment Share on other sites More sharing options...
Decky Posted March 23, 2014 Share Posted March 23, 2014 Firstly, on 500VA you do need soft starts. Secondly - these worked as a charm for me. http://diyclub.biz/catalog/product_info.php?cPath=1_248_153&products_id=402 They are not complicated circuits - Rod Elliot has a bit of writting on them: http://sound.westhost.com/project39.htm Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted March 23, 2014 Share Posted March 23, 2014 A total of 2,000VA of toroidal transformers will certainly require a softy start system. Properly engineered, a soft start system will not affect the sound of an amplifier in any way. Link to comment Share on other sites More sharing options...
rossb Posted March 23, 2014 Author Share Posted March 23, 2014 Do you run RCD's (Residual Current Devices) in the 'fuse box'? If so, I can provide the details of an RCD product that we use that should resolve the issue. I am not sure how easy it would be to fit them in a domestic situation but they solved a problem whereby power inrush was tripping our RCD's in a Data Centre. The devices that were tripping the circuits on power on are massive so you amps won't be an issue. A sparky should be able to advise you on their suitability for a domestic situation. The company might even have a scaled down version for domestic situations. It wasn't an inexpensive exercise but I had a lot to replace. Thanks, I have never heard of RCDs and don't know if there is one in the fuse box (probably not, I would guess), but I will certainly investigate this. Are you sure they have no soft start?. Otherwise i would recommend aussieamp soft start module. They would need to be wire with the primary side of the transformer. Quan Yes, I had an email from the Exposure head tech confirming this. Firstly, on 500VA you do need soft starts. Secondly - these worked as a charm for me. http://diyclub.biz/catalog/product_info.php?cPath=1_248_153&products_id=402 They are not complicated circuits - Rod Elliot has a bit of writting on them: http://sound.westhost.com/project39.htm Thanks, I will check these out. A total of 2,000VA of toroidal transformers will certainly require a softy start system. Properly engineered, a soft start system will not affect the sound of an amplifier in any way. Thanks, Trevor. How's your workload at the moment? Any chance you could install them for me? Link to comment Share on other sites More sharing options...
Zaphod Beeblebrox Posted March 23, 2014 Share Posted March 23, 2014 Pretty busy, both personally and professionally right now. I can do the job, but it will be a couple of weeks before I can get to it. Link to comment Share on other sites More sharing options...
rossb Posted March 23, 2014 Author Share Posted March 23, 2014 No problem, I will send you a PM. Link to comment Share on other sites More sharing options...
Telecine Posted March 24, 2014 Share Posted March 24, 2014 Attached is a PDF of the type of RCDs I was referring to earlier. At about $485 each they add up in cost when you need over 100. RCCB Type A SI Data Centre Schneider.pdf Link to comment Share on other sites More sharing options...
rossb Posted March 24, 2014 Author Share Posted March 24, 2014 Thanks for that. I think I do have RCDs but probably not to the same capacity. However, I think adding a soft start is probably a better way to go, so I can use the amps anywhere. 1 Link to comment Share on other sites More sharing options...
Telecine Posted March 24, 2014 Share Posted March 24, 2014 Thanks for that. I think I do have RCDs but probably not to the same capacity. However, I think adding a soft start is probably a better way to go, so I can use the amps anywhere. That sounds like a practical solution. Link to comment Share on other sites More sharing options...
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